Power ultrasound devices comprise of active component which converts electrical energy to mechanical energy. The vibrational output of the active component is transferred to a resonant structure (also referred to as horn, radiator, or resonator) which transfers the acoustic energy to the process fluids. The electrical energy transfer to the electro-mechanical device is generated by a power supply designed to deliver voltage close to the resonant frequency of the power ultrasound device. Present ultrasonic devices, such as longitudinally vibrating horns and the like, radially vibrating horns and the like, typically have small radiating surface area compare to its structural mass. Such devices concentrate high intensity acoustic energy to a very small surface area, generating an effective region that is confined to a very small volume near the tip of the device. Using such devices for fluids processes such as disinfection, agglomeration, deaeration, degassing, chemical reactions, catalysis, emulsification, deagglomeration, etc., would require that the ultrasound-assisted continuous process be limited to low flow rates of a few liters per minute or the ultrasound-assisted batch process be carried out at low volumes of a few liters and/or long processing times of a few minutes to a few hours. Typically, the increase in ultrasonic intensity or ultrasonic energy density by increasing the electrical energy to supply to the ultrasonic device can bring about an improvement in processing times and flow rates. However, an upper limit exists above which further increase in electrical energy will not generate useful acoustic energy due to the onset of the “bubble shielding” regime at high vibrational amplitudes. Because present devices have small radiating surface areas, the “bubble shielding” regime occur at relatively low input power levels. Therefore, a high-flow or high-volume ultrasound-assisted fluids processing application would require the use of a multitude of the ultrasonic horns, transducers, and power supplies to deliver the ultrasonic intensity or ultrasonic energy density required for the process. The use of multiple devices and their auxiliaries to meet the required process flow-rates and volumes increases capital and running costs. Newer power ultrasound devices attempt to overcome the above limitations by increasing the radiating surface area.
However, the increase in vibrating surface area is typically accompanied by a corresponding increase in the devices' structural mass. Thus, more electrical power is needed to resonate the device to the desired vibrational amplitude.